Читать книгу Wine Faults and Flaws - Keith Grainger - Страница 62

Occasionally, the presence of bubbles on a still wine could be indicative of a fault – either an alcoholic or malolactic fermentation (MLF) is taking place or has taken place in the bottle. This issue is discussed in Chapter 9. Cloudiness and/or presence of sludgy sediments might be a further indication of this. However, still wines in good condition may contain bubbles or petillance. Gases, namely carbon dioxide (CO₂), nitrogen (N), and argon (Ar) may be used as a blanket at various stages of winemaking to prevent oxidation or other spoilage. Particularly if a very fresh style of wine is desired, it is common to flush the vats with one of these gasses. Bottles too may be pre‐evacuated of oxygen and gas sparged immediately before filling. Some of the gas (particularly CO₂ which is highly soluble) may become dissolved in the wine – this does not generally detract from the quality, and can often add a sensation of freshness. Some wines, e.g. wines from the Mosel region of Germany may naturally retain some CO₂ from the alcoholic fermentation. In the case of still wines, a brief observation of the size and quantity of bubbles should be made. The bubbles may appear on the tasting glass surface, in which case they are likely to be large, on the rim, or in the heart of the wine.